It is important, in navigation or in metrology to know the distance or the change in distance with respect to a fixed location and/or the orientation of a movable object in space. A plurality of approaches are known today for determining the alignment of a movable object. For example, the orientation and movement of an object may be determined with the aid of inertial sensor systems, i.e. by magnetic field sensors, gyroscopes or acceleration sensors, and such a method and such an apparatus are respectively described in EP 1 521 165 A2. A disadvantage is that an unknown bias or offset of the sensors is contained in the measured variables which results in errors in the position and orientation result which increase over time. The error is usually determined and corrected by support measurements of other systems. Camera-based systems represent a further starting point for determining the orientation and, position of an object. In this respect, at least three markings are applied to the measured object which are detected by cameras and whose position and location toward one another are determined, whereby the measured object can be defined in space. Examples for this are described in DE 698 04 128 T2 and WO 99/21134.
An apparatus for measuring the alignment of a ship is described in GB 2 130 040 A using the GPS system. A rotating antenna or an arrangement of a plurality of antennas which behave like a rotating antenna by switching over in this respect receives radio signals from a satellite and the direction of incidence of the signal can be determined via the phase comparison between a rotation period of the antenna and a phase measurement, Doppler measurement, amplitude measurement or distance measurement which have a periodic profile. The alignment of the ship can be determined from this with the aid of the position of the satellite and of the ship's own position.